1. Field of the Invention
The present invention relates to a liquid cleansing composition suitable for topical application for cleansing the human body, such as the skin and hair. In particular, it relates to a lamellar structured liquid cleansing composition that is mild to the skin and which also exfoliates the skin.
2. The Related Art
Exfoliating liquid cleansing compositions are well known. However, the majority of them are not moisturizing. In addition the majority of them are not gentle enough for daily use while still providing the sensation and utility required of exfoliating particles.
Certain prior art liquid cleansing compositions with exfoliants have been described. U.S. Pat. No. 5,658,577 to Fowler et al., issued on Aug. 19, 1997 discloses an non-lamellar isotropic gel cleansing composition with very small exfoliant particles under 75 microns that are not perceptable to the user and that contains up to 20% of an hydrophobic emollient. U.S. Pat. No. 5,732,245 to Fowler et al., issued on May 19, 1998 discloses an non-lamellar isotropic liquid cleansing composition with very small exfoliant particles under 75 microns that are not perceptable to the user and that contains up to 50% of an hydrophobic emollient.
Surprisingly it has been found that mild liquid cleansing compositions having one or more syndet surfactants, one or more hydrophobic emollients at a level in excess of 10%, and exfoliants of a specific particle size range provide the user with enhanced moisturization and exfoliation simultaneously. This causes the user's exfoliated skin to appear fresh and healthy as it removes the dull layer of dead skin, accompanied with deep cleansing leading to less clogged pores while at the same time moisturizing the skin to minimize irritation and dryness as shown by various art recongnized techniques described below.
While not wishing to be bound by the following skin treatment theories, Applicants believe that exfoliation improves skin cleansing by helping to mechanically remove dirt and oil from the skin. Exfoliation also is believed to aid the process of desquamation. Desquamation is a natural process by which corneocytes are removed from the stratum corneum, which is the top layer of skin cells. Corneocytes are simply the cells that comprise the stratum corneum, and they are constantly being removed as the skin regenerates. Exfoliation aids in removing the flaky corneocytes that are ready to detach from the stratum corneum, and so promotes smoother, less flaky skin.
Other potential health benefits to exfoliation in addition to improved scale (flake) removal and oil removal, as suggested above, are reduction in bacteria on the skin, and increased blood flow to the skin due to the mechanical stimulation.
The inventive liquid cleansing composition under actual use conditions is expected to show improvements in skin softness, skin smoothness, and similar consumer perceived benefits such as exfoliation efficiency, mildness, moisturization efficiency, deposition efficiency, cleansing efficiency, and a liquid cleansing composition property such as skin abrasiveness, etc. based on changes from the baseline for these measurements using liquid cleansing compositions without the inventive composition as quantified using the test methods described below.
Applicants have discovered that a stable exfoliating liquid cleansing product can be prepared having a lamellar phase preferably having a viscosity in the range of about 80,000 cps to 300,000, more preferably about 50,000 to 150,000 (T-bar) at 25° C. Preferably the viscosity has an upper limit of 300,000 cps at 25° C. The lamellar phase and exfoliating particles preferably have different colors or other visual differences .